Prepare the cake: Preheat the oven to 350 degrees. Spray a 10-cup Fleur De Lis Bundt Pan with nonstick cooking spray; set aside.

Melt chocolate in a small bowl placed over a small saucepan of simmering water. Let cool 5 minutes. In a small bowl, combine wine and milk; set aside.

In the bowl of an electric mixer fitted with the paddle attachment, beat the butter and the granulated sugar on medium speed until light and fluffy. Add eggs; beat for 2 minutes. Add the cooled chocolate mixture and beat until incorporated, scraping down the sides of the bowl as necessary.

In a large bowl, whisk flour, gelatin, cocoa powder, baking powder, baking soda, and salt to combine. Add to mixer bowl, along with the wine mixture, and beat on low speed until combined, about 1 minute. Increase the speed to medium and beat for 2 minutes more, scraping down the sides of the bowl as necessary. Spoon batter into prepared pan.

Bake until a toothpick inserted into the center of the cake comes out clean, 40 to 45 minutes. Cool 15 minutes. Using a plastic knife, carefully loosen cake from the pan; invert onto a wire cooling rack. Let cool completely.

Prepare the glaze: Combine the butter, wine, and confectioners’ sugar in a medium saucepan. Bring to a boil, stirring occasionally, over medium-high heat. Remove from heat; stir in vanilla. Set aside until ready to serve.